Analysis of the oxocarboxylic acid fraction in serum and urine as O-methyloximes by thermionic specific detection.
After O-methyloximation of the carbonyl functions, the organic acids in serum and urine are extracted by anion-exchange chromatography, transformed into the methyl esters and pre-fractionated by thin-layer chromatography. In one of the four fractions and on the basis of the nitrogen in the O-methyloxime esters, the profiles of the oxocarboxylic acids are analyzed by gas chromatography with thermionic specific detection. The method has good specificity for the oxocarboxylic acids and is suitable for comparative studies. During diabetic or fasting ketoacidosis the serum concentrations of 3-oxobutyric acid and of the amino acid metabolites 2-oxobutyric, 2-oxoisovaleric and especially 2-oxo-3-methylvaleric and 2-oxoisocaproic acid are increased. In urine mainly 3-oxobutyric acid and only small amounts of the 2-oxocarboxylic acids are excreted.
D002849:Chromatography, Gas / Q000379:methods; D003920:Diabetes Mellitus / Q000097:blood / Q000652:urine; D016883:Diabetic Ketoacidosis / Q000097:blood / Q000652:urine; D006801:Humans; D007651:Keto Acids / Q000097:blood* / Q000652:urine; D011773:Pyruvates / Q000097:blood* / Q000652:urine; D019289:Pyruvic Acid; D014511:Uremia / Q000097:blood / Q000652:urine
D007651:Keto Acids; D011773:Pyruvates; C013082:alpha-ketoisocaproic acid; D019289:Pyruvic Acid